text: Plural endings are mostly the same across all three declension types with the exception of the genitive case.
  
  Genitive plural is indeed very irregular. My five year old son (Russian being his first language) still makes lots of mistakes in this form (кораблёв, лодков, варежков, etc).
  
  Here's a few general patterns to help you choose the ending (-ов/-ей or null):
  
  
  If nominative singular ends in -ь or a sibilant (ж/ш/щ/ч), then genitive plural will end in -ей: кора́бль - корабле́й, конь - коне́й, ночь - ноче́й, мать - матере́й, нож - ноже́й, мяч - мяче́й.
  Those ending in -а/-я in singular nominative will likely have a null ending in genitive plural: рука́ - рук, сторона́ - сторо́н, си́ла - сил, де́вушка - де́вушек, тро́йка - тро́ек, баня - бань. Some of these with the stem ending in a soft or sibilant have variants with -ей: свеча́ - свеч/свече́й, до́ля - доль/доле́й, дя́дя - дя́дей, ю́ноша - ю́ношей.
  Neuter nouns (ending in -о/-е/-ё) normally get a null ending: де́ло - дел, окно́ - о́кон, кре́сло - кре́сел, зда́ние - зда́ний, копьё - ко́пий. 
  The rest are likely to get the ending -ов/-ев/-ёв which is probably the largest category: стол - столо́в, дом - домо́в, ме́сяц - ме́сяцев, геро́й - геро́ев, солове́й - соловьёв.
  
  
  And of course there are lots of odd ones like во́лос - воло́с, глаз - глаз, челове́к - челове́к/люде́й, яйцо́ - яи́ц, о́блако - облако́в, etc. which have to be memorised separately. I'm only mentioning these because they are high-frequency words.
  
  These are the most generic rules. I'll stop here because otherwise this answer can get too involved. Let me know in the comments if you'd like it to be expanded to include smaller groups of nouns.
  
  P.S. I've written an article about Russian declension but it's in Russian.